• Study finds that the tongue of one bee species, the Bombus balteatus, has shrunk. (Photo: D. Sikes/Wikimedia Commons)

    Study finds that the tongue of one bee species, the Bombus balteatus, has shrunk. (Photo: D. Sikes/Wikimedia Commons)

The length of the tongues of two species of alpine bees found in Colorado got 24 per cent shorter over the last 40 years because the insects have had to adapt to feeding on flowers altered by climate change, scientists believe.

The Toronto Star reported that researchers in the joint U.S.-Canada study “believe the bees have rapidly adapted to feeding on shorter-tubed flowers, transforming them from long-tongued specialist pollinators to short-tongued generalists over the course of a few dozen generations — potentially disrupting their alpine environment.”

The study found that deep-tubed flowers are blooming less often on the slopes of three Rocky Mountain ridges, a change linked to increasingly warmer summers, the Star report said.

The Star said the study found that the length of the tongue of one species, Bombus balteatus, dropped to six millimetres from eight millimetres in one mountain-range population, while another species, Bombus sylvicola, saw a drop to just under four millimetres from just over five millimetres.